1. Field of the Invention
The present invention relates to precision positioning of a probe, and more particularly to an optically guided precision probe for use by a robot for accurately positioning a circuit microprobe at each of a number of very precise test locations on a miniaturized circuit.
2. Description of Related Art
Miniaturized integrated circuits and their miniaturized connecting boards have become so small and their circuits have been so miniaturized and have become so complex that manual methods of probing them for testing have become cumbersome and costly. The vast number of repetitions makes the probing operation tedious, and the precision requirements make the probing operation difficult or impossible to carry out without loss of accuracy of test or damage to the circuit under test.
Robot probing ends the tedium problem, helps with the cost problem, and is theoretically capable of precision unattainable by human operators without mechanical aids to precision, but the robot cannot currently compete with the marvelous combination of sensory perception and adaptive movement capability of the human operator. Specialized robot devices may, however, be equipped with sensory devices and accompanied by computer guidance features tied to the sensory devices so as to perform very specialized tasks with precision unmatched by human operators or earlier robots.
Mechanized handling of articles for assembly or test has long been a goal of production planners, and a great number of handling devices have been deployed, with degrees of adaptability varying from zero (hard tooling) to significant adaptability (soft tooling) depending primarily upon operator intervention for setup and control. The use of sensory devices associated with the mechanical gripper, cutting tool, test probe or other effector has been minimal.
U.S. Pat. No. 3,007,097, Shelley et al, AUTOMATIC HANDLING AND ASSEMBLY SERVOSYSTEM, Oct. 31, 1961, shows a lamp and photocell group system mounted on the movable effector to develop location data for the effector.
U.S. Pat. No. 3,502,882, Von Voros, OPTO-GRAPHICAL MEMORY AND DIGITALIZED CONTROL SYSTEM FOR PRECISION MACHINING, Mar. 24, 1970, shows optical sensing using fiber optics associated with the effector, arranged to follow a line on a template to provide positioning information for a slave effector which performs the actual cutting operation.
U.S. Pat. No. 3,532,807, (Webb-NASA) Wall et al, AUTOMATIC CLOSED CIRCUIT TELEVISION ARC GUIDANCE CONTROL, Oct. 6, 1970, shows a TV camera mounted on the effector of a seam welder to follow the seam. Light sources are also mounted on the effector to illuminate the seam.
U.S. Pat. No. 3,719,879, Marcy, SYSTEM FOR ACCURATELY POSITIONING AN OBJECT UNDER THE CONTROL OF PROGRAMMED NUMERICAL DATA, Mar. 6, 1973, shows a coarse-fine positioner for use in mask machines used for the manufacture of integrated circuits. A stepping motor provides the course positioning, and piezoelectric ceramics provide the fine displacement upon halting of the motor.
U.S. Pat. No. 3,786,332, Hepner et al, MICRO POSITIONING APPARATUS, Jan. 15, 1974, shows a precision positioning device using piezoelectric fine positioning transducers and a laser-mirror-interferometer system to provide position data, which with error calculation mechanism provides the necessary effector placement precision.
U.S. Pat. No. 3,888,362, Fletcher et al, COOPERATIVE MULTIAXIS SENSOR FOR TELEOPERATION OF ARTICLE MANIPULATING APPARATUS, June 10, 1975, shows an adaptive effector in the form of a manipulator arm with a complex photodetection system mounted near the gripper on the manipulator arm to provide X, Y and Z position data derived from related light emitting diodes reflecting off a specialized reflector on the target object.
U.S. Pat. No. 3,891,918, Ellis, LINEAR DISPLACEMENT TRANSDUCER UTILIZING AN OSCILLATOR WHOSE AVERAGE PERIOD VARIES AS A LINEAR FUNCTION OF THE DISPLACEMENT, June 24, 1975, shows a mechanical probe with displacement-sensitive solenoidal variable inductor.
U.S. Pat. No. 4,087,729, Yamazaki et al, POSITION FINELY ADJUSTING APPARATUS, May 2, 1978, shows a precision positioner using cylindrical piezoelectric transducers under the supervision of light beam detectors. A platform effector is supported by four bendable transducers and positioned by dynamic transducers.
U.S. Pat. No. 4,203,064, Suzuki et al, METHOD FOR AUTOMATICALLY CONTROLLING THE POSITION OF SMALL OBJECTS, May 13, 1980, shows a precision positioner with a resolver action operating by scanning and counting data marks on the target object.
The prior art does not show a precision microprobe with feedback position adaptability in X, Y and Z dimensions combined with pressure control.